The new outbreak of coronavirus from December 2019 has brought attention to an old viral enemy and has raised concerns as to the ability of current protection measures and the healthcare system to ...handle such a threat. It has been known since the 1960s that coronaviruses can cause respiratory infections in humans; however, their epidemic potential was understood only during the past two decades. In the present review, we address current knowledge on coronaviruses from a short history to epidemiology, pathogenesis, clinical manifestation of the disease, as well as treatment and prevention strategies. Although a great amount of research and efforts have been made worldwide to prevent further outbreaks of coronavirus‑associated disease, the spread and lethality of the 2019 outbreak (COVID‑19) is proving to be higher than previous epidemics on account of international travel density and immune naivety of the population. Only strong, joint and coordinated efforts of worldwide healthcare systems, researchers, and pharmaceutical companies and receptive national leaders will succeed in suppressing an outbreak of this scale.
The major impact produced by the severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) focused many researchers attention to find treatments that can suppress transmission or ameliorate the ...disease. Despite the very fast and large flow of scientific data on possible treatment solutions, none have yet demonstrated unequivocal clinical utility against coronavirus disease 2019 (COVID‑19). This work represents an exhaustive and critical review of all available data on potential treatments for COVID‑19, highlighting their mechanistic characteristics and the strategy development rationale. Drug repurposing, also known as drug repositioning, and target based methods are the most used strategies to advance therapeutic solutions into clinical practice. Current in silico, in vitro and in vivo evidence regarding proposed treatments are summarized providing strong support for future research efforts.
In mammalian cells, miRNAs (microRNAs) are the most abundant family of small non-coding RNAs that regulate mRNA translation through the RNA interference pathway. In general, it appears that the major ...function of miRNAs is in development, differentiation and homoeostasis, which is indicated by studies showing aberrant miRNA expression during the development of cancer. Interestingly, changes in the expression of miR-146a have been implicated in both the development of multiple cancers and in the negative regulation of inflammation induced via the innate immune response. Furthermore, miR-146a expression is driven by the transcription factor NF-kappaB (nuclear factor kappaB), which has been implicated as an important causal link between inflammation and carcinogenesis. In the present article, we review the evidence for a role of miR-146a in innate immunity and cancer and assess whether changes in miR-146a might link these two biological responses.
Despite high confidence in the treatment rationale and mechanisms of action, it appears that oligonucleotides delivered topically to the lung either rapidly access circulation via epithelial ...transcytosis or are removed by alveolar macrophages, exerting minimal, if any, action in the cytosol of cells relevant to lung disease. ...the use of cell-penetrating peptides, liposomes, or nanoparticle delivery systems has, so far, not been shown to eliminate circulatory clearance; may activate immune responses; or drive macrophage phenotypic changes that, together or in isolation, may present risks to patients.2 Importantly, the recently published study by Crosby et al.3 signifies a new addition to the evidence that airways disease, and cystic fibrosis (CF) patients in particular, may stand to benefit greatly from splicing modulator or RNase H-active ASO therapeutics when 3rd generation, so-called bi-cyclic or bridged (2′-4′ constrained) nucleoside chemistry is used. Elimination of ENaC hyperactivity in CF, which is thought to contribute to luminal solute imbalance and airway surface liquid volumes, has been long proposed as a promising treatment approach if persistent, rather than transient, ENaC activity downregulation can be achieved.6 This is supported by complementary data, including knockout of Nedd4L, a suppressor of ENaC that induces a CF-like phenotype in mice and is lethal by 3 weeks of age. ...using two different mouse models of CF, an adult mouse βENaC overexpression model and a Nedd4L knock-out neonate mouse model, the authors showed that ENaC-specific ASOs resulted in ∼50% (neonate) to ∼85% (adult) reduction of ENaC mRNA levels. ...these events support the rationale of applying careful, appropriate exploratory controls when inflammatory intervention is attempted before concluding fully on-target mechanisms of action. ...with the explicit absence of an on-target mechanism of action in the lung cells and evidence ruling out unexpected immunomodulatory effects, it remains to be proven whether the fascinating CF biomarker changes reported are indeed on account of the expected mechanism of action. Widespread adoption is likely to reduce assumptions around the translation of drug function across the drug development pipeline.19 Irrespective of historical data on what is and is not immunomodulatory in oligonucleotides versus the intricacies of nucleoside chemistry, a clinically proven and pharmaceutically relevant solution to achieving intracellular delivery, as recognized by Ionis for hepatic indications, involves the use of receptor-specific ligands. ...conjugation of N-acetyl-glucosamine (GalNAc) to oligonucleotide drugs has been shown to target the hepatocyte-specific asialglycoprotein receptor (ASGPR) and reduce drug doses by up to 60-fold in phase II clinical trials.20 Unfortunately, a prototype GalNAc-ASGPR pair suitable for oligonucleotide delivery into airways cells remains undiscovered but appears necessary.
At present, nothing is known of the role of miRNAs in the immune response in vivo despite the fact that inflammation is thought to underlie multiple acute and chronic diseases. In these ...circumstances, patients are commonly treated with corticosteroids such as dexamethasone.
To address this question, we have examined the differential expression of 104 miRNAs using real-time PCR during the innate immune response in mouse lung following exposure to aerosilised lipopolysaccharide (LPS). Following challenge, we observed rapid and transient increase in both the mean (4.3-fold) and individual levels of miRNA expression (46 miRNAs) which peaked at 3 hrs. Crucially, this increase was correlated with a reduction in the expression of tumour necrosis factor (TNF)-alpha, keratinocyte-derived chemokine (KC) and macrophage inflammatory protein (MIP)-2, suggesting a potential role for miRNAs in the regulation of inflammatory cytokine production. Examination of the individual miRNA expression profiles showed time dependent increases in miR-21, -25, -27b, -100, 140, -142-3p, -181c, 187, -194, -214, -223 and -224. Corticosteroid studies showed that pre-treatment with dexamethasone at concentrations that inhibited TNF-alpha production, had no effect either alone or upon the LPS-induced miRNA expression profile.
We have shown that the LPS-induced innate immune response is associated with widespread, rapid and transient increases in miRNA expression in the mouse lung and we speculate that these changes might be involved in the regulation of the inflammatory response. In contrast, the lack of effect of dexamethasone in either control or challenged animals implies that the actions of glucocorticoids per se are not mediated through changes in miRNAs expression and that LPS-induced increases in miRNA expression are not mediated via classical inflammatory transcription factors.
Background Although previous studies have implicated tissue CD4+ T cells in the development and maintenance of the inflammatory response in asthmatic patients, little is known about the role of CD8+ ...T cells. There is now accumulating evidence that microRNAs and other noncoding RNAs are important regulators of T-cell function. Objectives We sought to use transcriptomics to determine the activation state of circulating CD4+ and CD8+ T cells in patients with nonsevere and severe asthma. Methods mRNA and noncoding RNA expression in circulating T cells was measured by means of microarray, quantitative real-time PCR, or both. Results Comparison of mRNA expression showed widespread changes in the circulating CD8+ but not CD4+ T cells from patients with severe asthma. No changes were observed in the CD4+ and CD8+ T cells in patients with nonsevere asthma versus those in healthy control subjects. Bioinformatics analysis showed that the changes in CD8+ T-cell mRNA expression were associated with multiple pathways involved in T-cell activation. As with mRNAs, we also observed widespread changes in expression of noncoding RNA species, including natural antisense, pseudogenes, intronic long noncoding RNAs (lncRNAs), and intergenic lncRNAs in CD8+ T cells from patients with severe asthma. Measurement of the microRNA expression profile showed selective downregulation of miR-28-5p in CD8+ T cells and reduction of miR-146a and miR-146b in both CD4+ and CD8+ T cells. Conclusions Severe asthma is associated with the activation of circulating CD8+ T cells but not CD4+ T cells. This response is correlated with the downregulation of miR-146a/b and miR-28-5p, as well as changes in the expression of multiple species of lncRNA that might regulate CD8+ T-cell function.
Quorum sensing molecules (QSMs) regulate, through a chemical communication process, multiple complex systems in bacterial and some fungal populations on the basis of cell density. The bacterial QSMs ...involved in inter-kingdom cross-talk may exhibit antagonistic activity against fungi. This provides an important opportunity for biocontrol of fungal invasion in plants. It has been shown that cultures of
Bacillus
spp. inhibit fungal growth. Here, we explore the inhibitory potential of the industrial workhorse
Bacillus licheniformis
NCIMB-8874 and its QSM (ComX pheromone) on the growth of
Aspergillus flavus
, a cereal, legume, and nut crop pathogen. Our studies show that ComX filtered extracts from cultures of
B
.
licheniformis
can cause a significant reduction in the growth of
A
.
flavus
NRRL 3357 and ESP 15 at a concentration as low as 13 μg ml
−1
. This work evidences, for the first time, the inter-kingdom utility of the bacterial quorum sensing ComX pheromone indicating potential antifungal food security against
A
.
flavus
.
The discovery of an ever-expanding plethora of coding and non-coding RNAs with nodal and causal roles in the regulation of lung physiology and disease is reinvigorating interest in the clinical ...utility of the oligonucleotide therapeutic class. This is strongly supported through recent advances in nucleic acids chemistry, synthetic oligonucleotide delivery and viral gene therapy that have succeeded in bringing to market at least three nucleic acid-based drugs. As a consequence, multiple new candidates such as RNA interference modulators, antisense, and splice switching compounds are now progressing through clinical evaluation. Here, manipulation of RNA for the treatment of lung disease is explored, with emphasis on robust pharmacological evidence aligned to the five pillars of drug development: exposure to the appropriate tissue, binding to the desired molecular target, evidence of the expected mode of action, activity in the relevant patient population and commercially viable value proposition.
LncRNAs are involved in regulatory processes in the human genome, including gene expression. The rs35705950 SNP, previously associated with IPF, overlaps with the recently annotated lncRNA ...AC061979.1, a 1712 nucleotide transcript located within the MUC5B promoter at chromosome 11p15.5. To document the expression pattern of the transcript, we processed 3.9 TBases of publicly available RNA-SEQ data across 27 independent studies involving lung airway epithelial cells. Epithelial lung cells showed expression of this putative pancRNA. The findings were independently validated in cell lines and primary cells. The rs35705950 is found within a conserved region (from fish to primates) within the expressed sequence indicating functional importance. These results implicate the rs35705950-containing AC061979.1 pancRNA as a novel component of the MUC5B expression control minicircuitry.
High-throughput sequencing of the products of 5' RNA ligase-mediated rapid amplification of cDNA ends (5' RLM-RACE) reactions (RACE-SEQ) enables the mapping and digital enumeration of expected and ...novel 5' ends in RNA molecules. The resulting data are essential in documenting the mechanism of action and precision of endonucleolytically active, RNA-targeting drugs such as RNase H-active antisense or small interfering RNA. When applied to error-prone replication systems such as RNA viruses or in vitro RNA replicon systems, the method can additionally report the relative susceptibility of known and unknown polymorphisms to a prospective sequence-specific drug, making it a powerful tool in patient selection and stratification as well as resistance prediction.We describe the preparation of sequencing libraries for ultra-high depth 5' RLM-RACE analysis on two popular second-generation high-throughput sequencing platforms (Illumina, Ion Torrent) and supply a detailed bioinformatics analysis pipeline for target site activity definition and enumeration. We further illustrate how the pipeline can be simply modified to generate polymorphism-specific drug susceptibility data from in vitro replicon experiments (RACE-SEQ-MM), in a patient-free manner, to cover both known and unknown target site variants in the population.
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